#include <bits/stdc++.h>
using namespace std;

int main() {
    ios_base::sync_with_stdio(0);cin.tie(NULL);
    int n; cin >> n;
    string in;
    cin >> in;
    for(auto &c:in){
        c = (c+n>'z')? c+n-26 : c+n;
    }
    cout << in;
    return 0;
}
